New research shows that a preservation technique known as sequential
subnormothermic ex vivo liver perfusion (SNEVLP) prevents ischemic type
biliary stricture following liver transplantation using grafts from
donations after cardiac death (DCD). Findings published in Liver Transplantation,
a journal of the American Association for the Study of Liver Diseases
and the International Liver Transplantation Society, indicate that the
preservation of DCD grafts using SNEVLP versus cold storage reduces bile
duct and endothelial cell injury post transplantation.

The shortage of organs for liver transplantation
continues to pose a challenge for the transplant community, with up to
30% of patients on the liver transplant waiting list that die or are
delisted due to disease progression. One solution to increase available
organs is the use of marginal grafts, which include organs from older
donors, steatotic grafts, and livers obtained after cardiac death.
However, previous research reports that cold storage used to preserve
DCD livers are linked to 20% to 40% ischemic type biliary strictures
rate.

“While the use of marginal livers for transplantation
has increased the donor pool, it is not without issue,” explains lead
author Dr. Markus Selzner from Toronto General Hospital in Canada.
“Preservation techniques, such as cold storage, are not well tolerated
by marginal livers and can cause reperfusion or graft dysfunction. This
has prompted our investigation of preservation methods that avoid the
negative effects of cooling.”

For the present animal model study the research team
compared SNEVLP to cold storage of organs taken from pigs. Liver grafts
were stored for 10 hours at 4°C at 7 hours of cold storage and 3 hours
of SNEVLP at 33°C. Liver tissue (hepatocyte), endothelial cell and
biliary injury and function were measured.

Following transplantation the 7-day survival of the
animals was 60% in the SNEVLP and 40% in the cold storage groups.
There was no difference in the international normalized ration (INR),
factor V and aspartate aminotransaminase (AST) levels between the two
groups.

“Our findings suggest that cold storage followed by
SNEVLP protects the liver from bile duct injury and reduces endothelial
cell death,” concludes Dr. Selzner. “This preservation method increases
the donor pool by allowing better use of DCD liver grafts.” The
authors note that further investigation of this preservation method is
needed to understand the full impact on human livers used in
transplantation.